This invention generally relates to solar heaters and specifically relates to solar heating systems designed for heating a heat transfer fluid such as air or water for providing a supply of this heated fluid to a residential or commercial building.
Mankind has always benefited from the infrared rays of the sun to warm his surroundings and his personal being. Technologists have been at work throughout the centuries trying to develop apparatus for converting to useful purposes the sun's heat reaching the earth's surface.
During the early part of this century solar heating systems began to be developed for heating residential or commercial buildings. These solar heating systems invariably utilized collectors which acted as thermal heat exchangers by which the heat from the sun's rays could be absorbed into a heat transfer and conducting medium or fluid, i.e., air or water.
The recent oil embargoes and fuel shortages have promoted renewed interest in solar heaters. Developments have been directed toward focusing devices for concentrating the sun's rays upon an absorbing apparatus. These focusing devices have taken one of two general formats. The first is a parabollic reflector placed behind the absorbing apparatus which concentrates the reflected rays of the sun upon a focal point at which is located a heat absorbing or heat transfer apparatus. The second is a focusing lens placed intermediate the sun and the absorbing apparatus and is shaped to concentrate the sun's rays upon a focal point located on the absorbing apparatus.
Other developments have included rotating devices for rotating the focusing device from east to west throughout the day in order to catch the direct rays of the sun. Such rotating devices have normally been driven by a clock timer to catch the sun in the east at the beginning of the day and in the west at the end of the day.
Traditionally, non-rotating solar heat absorbing units have been canted at an angle of approximately 45.degree. with the horizon and have been positioned generally facing south. This orientation has permitted a maximum absorption of direct (perpendicular) rays from the sun throughout the solar heating day. The term "solar heating day" as used herein means those daylight hours during any day which the sun is in the sky and during which a solar heating system can be operated (i.e., the time between sunrise and sunset).
Many problems exist with these prior solar heating arrangements. These problems are centered around the relative inefficiency of these units. This inefficiency contributes to the relatively small heating capacity of such units which in turn contributes to the necessity for very large solar heat collectors or solar heat absorption panels. These very large panels become bery unsightly and cumbersome and heavy. Heavy absorption panels require a large structure such as the roof or walls of a building to support them. These panels have been placed on a southerly facing roof section of the building or when the building has a flat roof, have been placed on the top of such a flat roof surface. The efficiency of such a heating system is directly proportional to the heat absorption efficiency of the thermal heat absorbing panel which in turn is directly related to the angle at which it is oriented with respect to the direct rays of the sun.
An object of this invention is to provide a high efficiency solar heating system which requires a relatively small thermal heat absorbing unit.
A second object of this invention is to provide such a heating system which is capable of orienting the thermal heat absorption unit in two directions from east to west and from horizontal to vertical for aligning the thermal absorption unit orthogonally with the direction of the sun throughout the solar day and throughout the year.
Another object of this invention is to provide such a solar heating system wherein the heat absorption unit may be free standing and located away from the roof or other structural portion of a building being heated.
A further object of this invention is to provide a large thermal storage tank which may be heated to a desired temperature by the optimal operation of the solar heating system completely independently of the heating system (the heat transfer system) within the building.
An even further object of this invention is to provide an electrical control circuit or controlling the orientation of the thermal heat absorbing unit.